Contourable green with randomly operable contour selection

ABSTRACT

A contourable putting green ideally suited for use in indoor golf games including a contourable platform having an upper putting surface thereon and secured by tensioned springs to a parallel series of spaced, pivotally interconnected movable beams pivotally connected intermediate their ends to stationary beam support members. Motor driven self-reversing hydraulic jacks move the beams differentially to distort the platform and thereby vary the contour of the green. An electronic control circuit is provided for each jack, including an RC timer circuit having a discrete time constant, and is arranged so that operation of all of the jacks is simultaneously initiated by a master control switch, yet the operation of each jack continues to operate independently over its discrete period of time; resulting in unsynchronized movement of the various portions of the platform and a putting surface of substantially random contour.

Rogers et a1.

[ 1 Apr. 2, 197

[s41 CONTOURABLE GREEN WITH RANDOMLY OPERABLE CONTOUR SELECTION Dolce..273/l76 H X Primary Examiner-George J. Marlo Attorney-Hofgren, Wegner,Allen, Stellman and McCord [5 7] ABSTRACT A contourable putting greenideally suited for use in indoor golf games including a contourableplatform having an upper putting surface thereon and secured bytensioned springs to a parallel series of spaced, pivotallyinterconnected movable beams pivotally connected intermediate their endsto stationary beam support members. Motor driven self-reversinghydraulic jacks move the beams differentially to distort the platformand thereby vary the contour of the green. An electronic control circuitis provided for each jack, including an RC timer circuit having adiscrete time constant, and is arranged so that operation of all of thejacks is simultaneously initiated by a master control switch, yet theoperation of each jack continues to operate independently over itsdiscrete period of time; resulting in unsynchronized movement of thevarious portions of the platform and a putting surface of substantiallyrandom contour.

8 Claims, 3 Drawing Figures PATENTEB APR 2 5. I972 SHEEI 1 EF 2CONTOURABLE GREEN WITH RANDOMLY OPERABLE CONTOUR SELECTION BACKGROUND OFTHE INVENTION Because of the ever-increasing popularity of. the game ofgolf, there have been a number of proposals for indoor golf games as oflate to relieve the congestion on natural, outdoor courses. Such indoorgames are also intended to permit golfers to play golf year around insome of the less temperate zones and in both respects, such indoor golfgames have been suc cessful to a greater or lesser degree.

The primary factor affecting the degree of success of an indoor golfgame resides in the degree of sophistication of the equipment withrespect to realistically simulating conditions experienced by a golferon an outdoor course. In one commercialized game, realism has beensubstantially enhanced by providing a so-called contourable green toprovide the indoor golfer with realism in around the green and on thegreen play.

Such a contourable green generally comprises a relatively rigid butdistortable platform having an upper putting surface on which the golfermay walk and putt a golf ball towards a cup. Additionally, variousfringe areas and sand traps around the putting surface may be providedfor enhancing the realism of on the green play and in order to insurerealism, such contourable greens are relatively large in size. However,due to the fact that such greens must be housed in a building, it issomewhat impractical to make a contourable green of a size thatcompletely proximates the size of a natural outdoor green. As a result,such greens have typically been long and narrow with the result that foranything other than short length putts, the golfer may be putting fromvirtually the same position on the green for each shot.

In order to preclude the golfer from having substantially the same puttfor each hole for 18 different holes in an indoor game, heretofore suchgreens have utilized programming devices for controlling the contourthereof to provide a distinct green contour for each of the 18 holes.However, when a golfer plays an indoor game with a great deal offrequency, each time he plays the same hole, he may have substantiallythe same putt round after round.

It will be recognized that such will not normally occur on an outdoorcourse. Specifically, while the contour of an outdoor green is neverchanged, the cup location is frequently changed so that each time thegolfer plays the particular hole, he will be faced with a different puttdue to, at the very least, a change in cup location.

While cup locations on an indoor green could be changed, but not withoutdifficulty, any substantial change in cup location would have a tendencyto diminish the amount of putting surface available for extremely longputts and would cause untold confusion with respect to the use ofgrid-like markings for fringe areas or green areas at which the golferplaces the ball in accordance with infonnation provided to him by theremainder of the indoor golf game system.

As a result, a golfer playing an indoor golf game has heretofore beenfaced with some monotony in putting each time the same hole is playedwith the net result being a lesser degree of realism in simulatingoutdoor play.

SUMMARY OF THE INVENTION It is the principal object of the invention toprovide a new and improved contourable green for use in golf games.

More specifically, it is an object of the invention to provide a new andimproved contourable green wherein the contour of the green during itsuse as a golf game is randomly selected.

Another object is the provision of a contourable green including asupporting structure, a platform having an upper playing surface mountedon the supporting structure, motor means for moving the supportingstructure to distort the platform and thereby the playing surface andcontrol means for the motor means for randomly operating the motor meansso that the contour of the playing surface is randomly selected.

III

A further object is the provision of a contourable green such as thatset forth in the preceding paragraph wherein the motor means comprise atleast two powered means secured to the supporting structure at spacedlocations and the control means comprise two circuits, one for each ofthe powered means, for energizing the associated power means, with oneof the control circuits being operative to energize its associated powermeans for a longer period of time than the other circuit.

Another object is the provision of a contourable green such as that setforth above wherein the power means include hydraulic cylinders and thecontrol circuits include a RC network that determines the period ofenergization of the hydraulic cylinders.

Other objects and advantages will become apparent from the followingspecification taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a roomhousing a contourable green made according to the invention;

FIG. 2 is a side elevation of the contourable green structure; and

FIG. 3 is a schematic of the random control circuitry utilized in thegreen.

DESCRIPTION OF THE PREFERRED EMBODIMENT An exemplary embodiment of acontourable green made according to the invention is shown in theenvironment of a room, generally designated 10, housing indoor golf gameequipment. The room 10 includes side walls 12 and 14 and end walls 16and 18 and an access opening (not shown) into the room is also provided.

The side walls 12 and 14 have a significantly greater length than theend walls 16 and 18 and may be on the order of as much as feet long. Theend walls 16 and 18 may have a length in the neighborhood of 25 to 30feet. The purpose of the elongated configuration of the room 10 is suchthat a green may be housed therein which may provide putts of up to aslong as 60 feet as may be typically found on outdoor greens and yetminimize overall space requirements.

Within the room 10 is a contourable green which, in the exemplaryembodiment, consists of a fixed portion 20 and a contourable portion 22.The fixed portion 20 is elevated above the floor 24 of the room and willgenerally have its playing surface 26 in a horizontal plane. However,for the sake of realism, there may be provided a depressed playingsurface 28 in the fixed portion 20 and separated from the playingsurface 26 by means of a randomly contoured wall 30. In such a case, thedepressed playing surface 28 may consist of finely divided sandparticles and the randomly contoured wall 30 will be arranged to slopeupwardly and toward the contourable portion 22 to define a bunker fromwhich sand shots may be played.

The actual putting surface 36 may be formed of a short pile carpet orthe like and is defined by a closed line 34. The putting surface 36 islocated primarily on the contourable portion 22 although a small portionthereof is located on the fixed portion 20, the latter serving as astarting point for extremely long putts. A conventional golf cup 38including a flag stick 40 bearing a pennant 42 is located in the puttingsurface 36 relatively remotely from the fixed portion 20 and relativelyclose to the end wall 16. Preferably, a spacing on the order of about 15feet from the cup 38 to the end wall 16 is preferable in order to allowballs played from a point adjacent the end wall 18 to roll significantlypast the cup 38 if the golfer strikes them with too much force.

A fringe area 44 which may be formed of a carpeting having a somewhatlonger pile than the putting surface 36 completely surrounds the puttingsurface 36 on both the fixed portion 20 and on the contourable portion22. At various locations on the fringe 44, specialized lie mats forchipping purposes may be located. One such lie mat is illustrated at 46and interposed between the same and the putting surface 36 is a smallcorrugated surface 48 which will force the golfer to actually chip theshot from the lie mat 46 as opposed to putting it across the fringe 44to the green. The use of such a corrugated surface 48 enhances therealism of the game in that it compells an actual chip shot as opposedto a mere putt from certain locations off of the putting surface 36.

Referring now to FIGS. 1 and 2, the details of construction of the greenwill be described. The interface between the fixed portion 20 and thecontourable portion 22 is defined by a suitable framework 50 whichmounts a spaced pair of pivots 52 and 52' having their pivot axes in ahorizontal plane and extending generally transverse to the direction ofelongation of the room 10. A pair of pivot arms 54 and 54' are mountedfor rotation about the pivots 52 and 52' and in turn mount a pair ofspaced, conventional l-beams 56 and 56 for pivotal movement about thepivot points 52 and 52'. As the l-beam structures are identical only onewill be described. At the end of each l-beam 56 opposite the pivot arm54, there is located a second pivot arm 58, each of which mounts a pivot60. The pivot 60 pivotally interconnects each l-beam 56 to a respectivelink 62 which in turn mounts a second pivot point 64. The pivot point 64of each link 62 is, in turn, engaged with a pivot arm 66 on respectiveones of a pair of similar, conventional, spaced l-beams 68.

Each of the l-beams 68 is suspended above the floor 24 by means of apivotal connection 70 at the approximate midpoint of each l-beam 68. Thepivotal connection 70 has a horizontal axis running transverse to thedirection of elongation of the room 10 and is maintained in an elevatedposition with respect to the floor 24 by a suitable framework 72.

As a result of the just-described construction, it will be apparent thatthere are two green supporting beam structures each in turn comprised oftwo I-beams 56 and 68 which are pivoted together at their point ofadjacency with each l-beam 56 further pivoted to a fixed structure bypivot point 52. Mounted on the two beam structures comprised of thelbeams 56 and 68 is a rigid but distonable platform. In the exemplaryembodiment, the rigid but distortable platform is formed of% inchplywood sheets 74 mounted on two-by-fours 76 which extend across thespaced beam sections defined by the l-beams 56 and 68. By means ofrelatively heavy springs 78 secured by any suitable means to either theplywood sheets 74 or the two-by-fours 76, the platform is resilientlysecured to the l-beams 56 and 68. Specifically, the springs 78 areinterposed between the platform and the l-beams 56 and 68 and secured tothe latter by means of cleats 80. As a result of the just-describedconstruction, it will be apparent that movement of the I-beams 56 and 68will yieldably draw the platform including the plywood sheets 74 and thetwo-by-fours 76 with the l-beams 56 and 68 to distort the platformthereby providing something other than a planar contour for putting andchipping purposes.

Such movement of the l-beams 56 and 68 and their counterparts 56 and 58'is provided by means of double acting hydraulic jacks 82 and 82 whichare pivotally attached such as at 84 to a bracket 86 secured to thefloor 24. As the operation of the jacks 52 and 82 are identical, theoperation of jack 82 alone will be described. The double actinghydraulic jack 82 has its piston rod 88 secured to either one of thepivots 60 or 64 at the interface between the I-beams 56 and 68.

As a result of the just-described construction, it will be appreciatedthat application of fluid under pressure to the hydraulic jack 82 willeither cause the adjoining ends of the lbeams 56 and 68 to be raised orlowered thereby elevating or depressing that portion of the platformimmediately above the cylinders 82. Because of the presence of the pivot70, that portion of the platform over the right-most end of the I-beam68 as viewed in FIG. 2 will be depressed or raised then the portion ofthe platform over the cylinders 82 is raised or depressed, respectively.During such movement, by virtue of the resilient connection of theplatform to the beams, the platform will tend to separate from the beamsso that there is not an abrupt discontinuity at the joint between thebeams 56 and 68 resulting in the platform, with the fringe 44 and theputting surface 36 on the upper surface thereof, having an upper,rolling surface closely akin to that found on a natural, outdoor green.

it should also be noted that in the course of such movement, thetendency of the adjacent ends of the beams 56 and 68 to separate due tothe fact that they are pivoted respectively at the fixed pivots 52 and70 is accommodated by the presence of the link 62 which is pivoted tothe beam 56 at pivot 60 and to the beam 68 at the pivot 64.

Before describing the control circuit for the hydraulic jacks 82 and82', some mention should be made of the details of construction of theconventional double acting jacks Each conventionally includes areversing valve which, when the cylinder piston reaches its full extentof travel in either direction, will be actuated to reverse theapplication of fluid under pressure to the piston so that the directionof piston travel is reversed. This feature permits a simplified controlwithout any requirement for servo mechanisms or bidirectional motors.Additionally, conventional check valve systems are employed so that whenfluid under pressure is not being applied to the cylinders, the pistonsthereof will not be permitted to change position.

The exemplary embodiment of the control circuit is illustrated in FIG. 3and inasmuch as the control circuit for each of the jacks 82 and 82 issimilar but not identical, reference will be made primarily to but oneof the circuits with the difference in the second circuit beingexplained.

A source of line power is provided and is connected through aconventional circuit breaker 102 for protective purposes to the primarywinding of a transformer 104. The secondary winding of the transformer104 is connected as an input to a conventional full wave rectifier 106and the output of the rectifier 106 is applied across a Zener diode 108to limit the maximum voltage applied to the remainder of the controlcircuit.

A manually operable switch 110 is located on one side of the output ofthe full wave rectifier 106 and, as will be seen hereinafter, may bemanually actuated by a golfer to randomly change the contour of thegreen. From the switch 110, the line passes through a diode 112 to arelay coil 114 which is connected in series with a transistor 116 and inparallel with a diode 118.

Contacts 120 are adapted to be closed when the coil 114 is energized andhave one side thereof connected to the anode of the diode 112 and aresistor 122. The resistor in turn is connected to a control terminal ofan electronic switch 124 of conventional construction interposed betweena lead 126, which is connected in common to the output of the rectifier106 as well as the power source 100, and a load in the form of ahydraulic pump 128. The circuit is completed by connecting the hydraulicpump 128 through a conventional circuit breaker 130 used for protectivepurposes to the other side of the power source 100. As a result, it willbe apparent that when the electronic switch 124 is caused to conduct,the hydraulic pump 128 will be energized.

Returning to the transistor 116, it will be seen that its base isconnected to the common junction of a resistor 132 and the anode of asilicon controlled rectifier 134. The cathode of the silicon controlledrectifier 134 is connected to the anode of the diode 112 while theresistor 132 is connected to the common line 126.

The gate of the silicon controlled rectifier is connected to the commonjunction of a resistor 136 and a unijunction transistor 138. Theunijunction transistor is connected through a resistor 140 to the commonline 126 and through the resistor 136 to the anode of the diode 112.

The trigger of the unijunction transistor 138 is connected to an RCcircuit comprised of a relatively large capacitor 141 and a resistorcomprised of a fixed resistor 142 and a variable resistor 144. Morespecifically, the connection of the trigger of the unijunctiontransistor is to the junction of the capacitor 141 and the variableresistor 144.

The operation of the system is as follows. Initially, the entire circuitis deactivated except that power is available from the rectifier 106.When a golfer, in readiness to putt on the contourable green, desires achange in the contour of the same, he will momentarily close the switch110 by manually depressing the same and the momentary closing of theswitch 110 together with the bias applied to the base of the transistor116 through the resistor 132 will cause a circuit from the common line126 through the transistor 116 and the coil 114 to be completed. Thiswill result in the contacts 120 being closed and the same serve as aholding circuit to bypass the switch 110 which opens after its initialdepression. At the same time, power is applied through the resistor 122to the electronic switch 124 thereby causing energization of thehydraulic pump 128. Energization of the hydraulic pump 128 will thencause operation of the corresponding hydraulic cylinders 82. Of course,due to the construction of the hydraulic cylinders, it cannot bepredicted at this time whether the associated cylinder piston willextend or retract.

The application of power to the above circuit either through the closingof the switch 110 or the closing of the contacts 120 also results inpower being applied across the RC circuit comprised of the capacitor 141and the resistors 142 and 144. As a result, the capacitor 141 will beginto charge and after a predetermined time period determined by theresistance values of the resistors 142 and 144 as well as thecapacitance of the capacitor 141 and the characteristics of theunijunction transistor 138, the unijunction transistor 138 will befired. When the unijunction transistor 138 is fired, there will be achange in the potential level at the junction thereof and the resistor136 which, it will be recalled, is connected to the gate of the siliconcontrolled rectifier 134. This change will cause the silicon controlledrectifier 134 to fire and as a result, a path of conduction will beestablished through the resistor 132 and the silicon controlledrectifier 134. This conduction will then cause a voltage drop across theresistor 132 thereby changing the bias applied to the base of thetransistor 116 to cause the same to revert to a non-conducting state. Ofcourse, when the transistor 116 is not conducting, the coil 114 cannotbe energized and the contacts 120-will open. As a result, the electronicswitch 124 will be turned off thereby de-energizing the hydraulic pump128 and stopping movement of the associated hydraulic cylinder 82.

At the termination of movement of the associated hydraulic cylinder 82,the control circuit therefor described above automatically resets itselfto be in readiness for a subsequent operation. Specifically, the chargeon the capacitor 141 is reduced to zero by means of a path including theresistors 142 and 144, the line 126, the resistor 132 and the siliconcontrolled rectifier 134. As soon as the charge on the capacitor 141 hasbeen reduced to zero, the silicon controlled rectifier 134 and theunijunction transistor 138 will revert to a nonconducting state and willbe rendered conducting again only when the unijunction transistor 138has again been fired.

The control circuit for the second one of the hydraulic jacks 82' issubstantially identical to that just described with the exception thatthe position of adjustment of the wiper of the variable resistor 144 ischanged from that used in the circuit described above thereby alteringthe time period determined by the RC characteristics of the resistors142 and 144 and the capacitor 141. As a result, the closing of theswitch 110 and the second jack 82 will be operated for a period of timediffering from the period of time of operation from the first jack 82 asdetermined by the difference in the position of the wiper of thevariable resistor 144 in their respective control circuits.

Because both cylinders are operated for different periods of time anymay be operated prior to the putt for each group of golfers playing ahole, it will be appreciated that the contour of the putting surfacewill be relatively randomly selected so that a golfer will not be facedwith substantially the same putt each time he plays a given hole on anindoor golf game. A further contributing factor to the random selectionof the green contour is the use of hydraulic cylinders as jacks.

Specifically, because of the load continually placed on the jacks, itwill be appreciated that a given period of operation of the hydraulicpump for each jack will cause less upward movement of the platform thandownward movement due to the gravity assist provided by the weight ofthe contourable green. When this factor is coupled with the differencesin times of operation of each jack, a virtually truly random contourselection is obtainable, thereby eliminating virtually all possibilityof the golfer being faced with substantially identical putts from timeto time and significantly enhancing the realism of an indoor golf game.

While the preferred embodiment as described employs electronic timers toachieve a random contour, the invention is not to be so limited exceptas stated in the appended claims. The electronic timers described hereinare the preferred form of timer because of the high reliabilityobtainable with solid state devices. However, in some instances, adegree of reliability may be sacrificed for a more economicalconstruction and in such cases, any suitable switch operating mechanicalor electromechanic timing movement may be used in lieu of the electronic timer specifically described. Of course, two such devices must beemployed and each should have a different time period of operation.

Having described the preferred embodiment of the invention, we do notwish to be limited to the details set forth, but rather to have ourinvention construed according to the true spirit thereof as set forth inthe following claims.

We claim:

1. In a contourable green for a golf game including a supportingstructure, a platform having an upper playing surface mounted on thesupporting structure, and means for moving the supporting structure todistort the platform and thereby the. playing surface, an improvementwherein said moving means comprises a plurality of independentlyoperated selfreversing power operating means for reciprocally movingportions of the platform up and down over a preselected vertical rangeand means to control said moving means comprising an electronic timercircuit for each of said power operating means said timer circuit beingoperative upon initiation to activate its associated power operatingmeans for a preselected period of time, said operative time periodsbeing so related to the operating speed and vertical range of saidself-reversing power operating means as to result in each stoppingsequentially at a multitude of unique vertical positions upon successiveperiods of operation, and manually operated means for simultaneouslyinitiating each of said timer circuits; whereby said upper playingsurface is caused to sequentially assume a great multitude of uniquethree dimensional contours upon successive actuations of said manualoperating means.

2. A contourable green according to claim 1 wherein each of said poweroperated means comprises a motor driven hydraulic pump and a doubleacting hydraulic cylinder, and wherein each of said timer circuits isoperative to energize one of said motor driven hydraulic pumps.

3. A contourable green according to claim 2 wherein each of said timercircuits includes an RC circuit operative to deenergize said motordriven hydraulic pump after a predetermined time period dependent uponthe electrical characteristics of said RC circuit.

4. A contourable green according to claim 3 wherein the RC circuit ofthe timer circuit for one of said motor driven hydraulic pumps is set tohave a different time constant than the RC circuit for the other of saidpumps.

5. A contourable green for use in a golf game comprising: a rigid butdistortable platform having an upper playing surface; a plurality oflaterally spaced beam structures supporting said platform, each saidbeam structure .being comprised of a plurality of pivotallyinterconnected beams; means mounting each said beam for pivotal movementin the vertical plane; means yieldably securing said platform to saidbeams; at least two double acting hydraulic cylinders, each interposedbetween a stationary structure and one of said beam structures andconnected to the latter at a point remote from said pivotal mountingmeans for each beam; at least two energizable hydraulic pumps forproviding fluid under pressure to an associated one of said hydrauliccylinders; and means for energizing each of said energizable pumps, saidenergizing means comprising a plurality of electrical circuits, one foreach pump, and having a common master actuating switch adapted to bemomentarily closed by a golfer for applying power simultaneously to saidcontrol circuits, each said circuit further comprising means to energizean associated pump upon the actuating of said master switch and means tode-energize said pump at the expiration of a predetermined time intervalincluding an RC circuit energizable upon the closing of said masterswitch and responsive to a predetermined charge thereon, the RC circuitof one of said control circuits having a different time constant thanthe RC circuit for another of said control circuits.

6. A variably contourable playing surface comprising: a supportingstructure a rigid but distortable platform the top surface of whichcomprises a playing surface and means for movably supporting saidplatform upon said supporting structure, means to vary the contour ofsaid playing surface comprising a plurality of power driven units eachvarying the elevation of an associated portion of said platform over apredetermined vertical range as a function of time in operation, saidpower driven units being self-reversing at the upper and lowerextremities of the predetermined vertical range, and

means to control the operation of said plurality of power driven unitsincluding means to commonly initiate operation of said units and meansincluding an electronic time constant circuit to independently terminatethe operation of each of said power driven means upon the expiration ofdiscrete time intervals selected to cause each of said power drivenmeans to move to a substantially unique position upon each such commoninitiation.

7. The device of claim 6 wherein said means to control said plurality ofpower units comprises a manually operable switch adapted to bemomentarily closed by a golfer, a control circuit for each of said powerunits energized upon closing of said manually operable switch, means ineach of said control circuits operable upon the momentary closing ofsaid manually operable switch for maintaining said circuit energized fora preselected time period, including an RC network in each said circuithaving a different time constant than the RC network in any other ofsaid circuits.

8. The device of claim 6 further including means attaching said platformto said contour varying means, said attaching means comprising tensionedelements urging said rigid platform into contact with said contourvarying means.

1. In a contourable green for a golf game including a supportingstructure, a platform having an upper playing surface mounted on thesupporting structure, and means for moving the supporting structure todistort the platform and thereby the playing surface, an improvementwherein said moving means comprises a plurality of independentlyoperated self-reversing power operating means for reciprocally movingportions of the platform up and down over a preselected vertical rangeand means to control said moving means comprising an electronic timercircuit for each of said power operating means said timer circuit beingoperative upon initiation to activate its associated power operatingmeans for a preselected period of time, said operative time periodsbeing so related to the operating speed and vertical range of saidself-reversing power operating means as to result in each stoppingsequentially at a multitude of unique vertical positions upon successiveperiods of operation, and manually operated means for simultaneouslyinitiating each of said timer circuits; whereby said upper playingsurface is caused to sequentially assume a great multitude of uniquethree dimensional contours upon successive actuations of said manualoperating means.
 2. A contourable green according to claim 1 whereineach of said power operated means comprises a motor driven hydraulicpump and a double acting hydraulic cylinder, and wherein each of saidtimer circuits is operative to energize one of said motor drivenhydraulic pumps.
 3. A contourable green according to claim 2 whereineach of said timer circuits includes an RC circuit operative tode-energize said motor driven hydraulic pump after a predetermined timeperiod dependent upon the electrical characteristics of said RC circuit.4. A contourable green according to claim 3 wherein the RC circuit ofthe timer circuit for one of said motor driven hydraulic pumps is set tohave a different time constant than the RC circuit for the other of saidpumps.
 5. A contourable green for use in a golf game comprising: a rigidbut distortable platform having an upper playing surface; a plurality oflaterally spaced beam structures supporting said platform, each saidbeam structure being comprised of a plurality of pivotallyinterconnected beams; means mounting each said beam for pivotal movementin the vertical plane; means yieldably securing said platform to saidbeams; at least two double acting hydraulic cylinders, each interposedbetween a stationary structure and one of said beam structures andconnected to the latter at a point remote from said pivotal mountingmeans for each beam; at least two energizable hydraulic pumps forproviding fluid under pressure to an associated one of said hydrauliccylinders; and means for energizing each of said energizable pumps, saidenergizing means comprising a plurality of electrical circuits, one foreach pump, and having a common master actuating switch adapted to bemomentarily closed by a golfer for applying power simultaneously to saidcontrol circuits, each said circuit further comprising means to energizean associated pump upon the actuating of said master switch and means tode-energize said pump at the expiration of a predetermined time intervalincluding an RC circuit energizable upon the closing of said masterswitch and responsive to a predetermined charge thereon, the RC circuitof one of said control circuits having a different time constant thanthe RC circuit for another of said control circuits.
 6. A variablycontourable playing surface comprising: a supporting structure a rigidbut distortable platform the top surface of which comprises a playingsurface and Means for movably supporting said platform upon saidsupporting structure, means to vary the contour of said playing surfacecomprising a plurality of power driven units each varying the elevationof an associated portion of said platform over a predetermined verticalrange as a function of time in operation, said power driven units beingself-reversing at the upper and lower extremities of the predeterminedvertical range, and means to control the operation of said plurality ofpower driven units including means to commonly initiate operation ofsaid units and means including an electronic time constant circuit toindependently terminate the operation of each of said power driven meansupon the expiration of discrete time intervals selected to cause each ofsaid power driven means to move to a substantially unique position uponeach such common initiation.
 7. The device of claim 6 wherein said meansto control said plurality of power units comprises a manually operableswitch adapted to be momentarily closed by a golfer, a control circuitfor each of said power units energized upon closing of said manuallyoperable switch, means in each of said control circuits operable uponthe momentary closing of said manually operable switch for maintainingsaid circuit energized for a preselected time period, including an RCnetwork in each said circuit having a different time constant than theRC network in any other of said circuits.
 8. The device of claim 6further including means attaching said platform to said contour varyingmeans, said attaching means comprising tensioned elements urging saidrigid platform into contact with said contour varying means.